• Energy Research

In this study, our aim was to explore the potential energy savings obtainable from the recycling of 1 tonne of Construction and Demolition Waste (C&DW) generated in the Metropolitan City of Naples. The main fraction composing the functional unit are mixed C&DW, soil and stones, concrete, iron, steel and aluminium. The results evidence that the recycling option for the C&DW is better than landfilling as well as that the production of recycled aggregates is environmentally sustainable since the induced energy and environmental impacts are lower than the avoided energy and environmental impacts in the life cycle of recycled aggregates. This LCA study shows that the transition to the Circular Economy offers many opportunities for improving the energy and environmental performances of the construction sector in the life cycle of construction materials by means of internal recycling strategies (recycling C&DW into recycled aggregates, recycled steel, iron and aluminum) as well as external recycling by using input of other sectors (agri-food by-products) for the manufacturing of construction materials. In this way, the C&D sector also contributes to realizing the energy and bioeconomy transition by disentangling itself from fossil fuel dependence.

In the challenge of transforming waste into useful products that can be re-used in a circular perspective, Italian wine industry can represent a suitable model for the application of the bioeconomy principles, including the valorisation of the agricultural and food waste. In the present study, a comprehensive environmental assessment of the traditional production of wine was performed and the potentiality of a biorefinery system, based on winery waste and aimed at recovering useful bio-based products, such as grapeseed oil and calcium tartrate, was examined through Life Cycle Assessment (LCA). The wine company "I Borboni", producing Asprinio wine in the Campania Region (Italy), was proposed as a case study. The hotspots of the linear production system were identified and the bottling phase, in particular the production of packaging glass, resulted to contribute to the generation of impacts at 63%, on average, versus 14.3% of the agricultural phase and 22.7% of the vinification phase. The LCA results indicated human carcinogenic toxicity, freshwater eutrophication and fossil resource scarcity impact categories as the most affected ones, with normalized impacts amounting to 9.22E-03, 3.89E-04 and 2.64E-04, respectively. Two side production chains (grapeseed oil and tartrate production) were included and circular patterns were designed and introduced in the traditional production chain with the aim of valorising the winery residues and improving the overall environmental performance. By implementing the circular approach, environmental impacts in the global warming, freshwater eutrophication and mineral resource scarcity impact categories, in particular, resulted three times lower than in the linear system. The results achieved demonstrated that closing the loops in the wine industry, through the reuse of bio-based residues alternatively to fossil-based inputs within the production process, and integrating the traditional production system with new side production chains led to an upgrade of the wineries to biorefineries, towards more sustainable production patterns.

The appropriate transformation and valorisation of biogas offers environmental and economic opportunities in a future with restrictions upon fossil-based fuels and materials. The LCA method was used to quantify and compare the potential environmental impacts of an AD plant incorporating biogas co-generation and upgrading options, namely AD-CHP and AD-RNG. Using an average Anaerobic Digestion facility in Ontario, Canada, modelled after real facilities, as a case study, electricity and steel were identified as potential hotspot input materials carrying a disproportionate environmental burden for biogas production. With a system expansion approach, the biogas was subsequently utilized to produce (1) both heat and electricity using a Combined Heat and Power (CHP) system, or (2) upgraded to renewable natural gas (also called biomethane) through chemical amine scrubbing, respectively.In comparing the biogas co-generation and upgrading options, the AD-CHP alternative resulted in a lesser environmental load, two times lower when compared to the AD-RNG biomethane recovery option. Furthermore, the avoided burden of producing fossil-based electricity, natural gas, and chemical fertilizer was analyzed and compared against their renewable counterparts. Significant reductions in emissions and in the depletion of fossil fuels were achieved, thus confirming the positive efforts of diverting organic waste from landfills to reduce organic waste disposal impacts and improve the management of organic waste. The analysis has provided useful insights to bioenergy project developers, policy makers and the scientific community regarding the processing of source separated organic waste, biogas production, and its upgrading alternatives in a circular economy perspective.

Purpose: The olive oil sector in Italy has a significant socio-economic, environmental, and cultural relevance. However, the environmental impacts of production and consumption models are considerable, mainly due to the demand for large quantities of resources (fuels, chemicals) and to the environmental impacts of residues’ disposal. Due to the scarcity of resources and climate change concerns, circular economy principles based on industrial ecology concepts are emerging. In this paper, the principles of circular economy were specifically applied to the olive oil supply chain, to improve the environmental sustainability of the sector. Methods: The production chain of extra virgin olive oil was analyzed using the Life Cycle Assessment method, based on primary data from an oil farm and mill in Southern Italy. The environmental impacts were evaluated through the SimaPro software and the ReCiPe 2016 Mid-point (H) Impact Assessment Method, with reference to the functional unit of 1-L bottle of extra virgin olive oil. Some circular improvement options were investigated, comparing the impacts generated by (i) extra virgin olive oil linear production without valorization of by-products, (ii) extra virgin olive oil linear production with allocation of total impacts to co-products, and (iii) two circular production systems, incorporating improvements such as replacement of diesel with biodiesel and of electricity from the national grid with energy recovered from residues. Results and discussion: The environmental impacts of the business-as-usual production pattern were identified for possible improvements. In all phases of the production chain of organic extra virgin olive oil, the most affected impact categories were human carcinogenic toxicity, marine ecotoxicity, and terrestrial ecotoxicity. As expected, the major contributions to almost all the analyzed impact categories were determined by the agricultural phase (92.65%), followed by the bottling phase (7.13%) and the oil extraction phase (0.22%). The valorization of by-products was considered by widening the system boundaries to ensure the environmental sustainability by developing circular patterns that feedback waste materials to upstream steps of the same process. The environmental impacts resulted lower in almost all the impact categories, with the major benefits gained in the global warming and fossil depletion impact categories. Conclusions: The analysis proved that the reuse of pomace, prunings, and exhausted cooking oil initially considered as waste can bring benefits from an environmental point of view to the larger scale of the economy, by replacing fossil fuels, as well as to the olive oil chain itself, by providing the needed energy for production.